As is known, the mixes used to produce outer tyre portions also contain wax to protect the outside of the tyre from decay caused by the rubber reacting with ozone in the air. In fact, chemical attack by ozone is thought to be one of the main causes of ageing in tyres.
To counteract such ageing, mixes used to produce outer tyre portions contain wax, which protect the rubber from ozone attack by migrating to the surface and forming a protective film about the tyre.
Though successful in protecting the rubber from ozone attack, the wax solution has the drawback of the surface film impairing the look of the tyre, so considerable time and expense are incurred by tyre manufacturers and/or retailers in cleaning the tyres for sale.
Outer tyre portion mixes normally contain a standard paraffin wax comprising at least 60% by weight of normal paraffin.
Though satisfactory in terms of ozone protection, this standard wax does not always meet market demand in terms of appearance.